Consider the following statements regarding Mongol invasions of Delhi Sultanate territory:

1. The first Mongol invasion of Delhi Sultanate territory took place during the reign of Jalal-ud-din Khalji.

2. A Mongol force marched up to and besieged Delhi during the reign of Ala-ud-din Khalji.

3. Muhammad-bin-Tughlaq permanently lost significant Sultanate territory to the Mongols.

How many of the statements given above are correct?